1. Field of the Invention
The present invention pertains to a lens apparatus and imaging apparatus applicable in surveillance cameras that record images during the day and at night.
2. Description of the Related Art
Conventionally, imaging apparatuses, such as surveillance cameras that record images during the day and at night, switch between recording images using visible light and infrared light. Among such imaging apparatuses, is an apparatus that includes an infrared (IR) filter that transmits infrared light and a motor that changes the position of the IR filter, and depending on the type of light used for recording an image, the apparatus changes the position of the IR filter to be aligned on the optical path or to be deviated from the optical path.
Another conventional technology, such as that disclosed in Japanese Patent Application Laid-Open Publication No. 2003-348398, includes a switch member that can block or allow infrared light to enter. The switch member is integrated with a diaphragm member that adjusts the amount of light. Furthermore, a conventional technology disclosed in Japanese Patent Application Laid-Open Publication No. 2005-352160 includes a diaphragm unit provided in a lens barrel and enables an optical filter to be inserted into and removed from the lens barrel in proximity to the diaphragm unit.
The insertion and removal of the optical filter is performed by pulling a member provided on a frame holding the optical filter. The optical filter is provided in the lens barrel and this technology further enables the diaphragm unit to be inserted into or removed from the lens barrel in proximity to the optical filter.
However, for the conventional technologies respectively disclosed in Japanese Patent Application Laid-Open Publication Nos. 2003-348398 and 2005-352160, when a device (a lens apparatus, an imaging apparatus employing the lens apparatus) that does not require an IR cut filter is to be manufactured, the lens barrel must be swapped at assembly as the lens barrel is a common part.
Although the only difference between an existing device and a new device is whether an optical filter is provided, the lens barrel including the optical filter must be swapped and as a result, the swap may be performed for a device for which the swap is not necessary, thereby causing unnecessary costs. Additionally, when there are various models of a device, the number of parts used to manufacture each model increases, thereby complicating parts management. The complication of parts management further causes problems in that the cost involved in part swapping and parts management increases.